One of the best things about the many Android-powered eReaders on the market today is that they are very hackable. Android as the background operating system allows users to unlock the devices and install all manner of apps that the manufacturer probably never intended. One of those hackable eReaders is the Nook Simple Touch.
A video has turned up on YouTube that shows a Sega Genesis emulator running on the Simple Touch. Not only is the emulator running a Sonic the Hedgehog game, it appears to be impressively smooth and playable as well. Granted the screen on this tablet is a simple black and white E Ink unit.
I think it would get old playing video games on a black-and-white screen very quickly. The person who uploaded the video goes by ndncnbvcuyuys and points out that the controls have a slight delay. Another caveat to installing the emulator on the eReader is that you have to jailbreak the device.
You also have to install another app called the NoRefresh app to prevent constant refreshing. The Nook Simple Touch runs Android 2.1. I think this is probably one of those projects for people who just like to tweak their hardware rather than someone looking for a portable game device.